- Email: [email protected]
Prejudice linked to female fertility cycle
For new stories every day, visit www.NewScientist.com/news
Brian Stablyk/getty
INGENIOUS experiments that have teased apart the mind-altering and pain-relieving effects of cannabis could open the way to related drugs that offer pain relief without causing unwanted highs. Medicinal cannabis is taken as a painkiller – to dull pain in cancer and multiple sclerosis for example – but it can produce unpleasant side effects such as hallucinations and impaired mobility. Now, Li Zhang at the US National Institute on Alcohol Abuse and Alcoholism in Bethesda, Maryland, and colleagues have shown that tetrahydrocannabinol (THC) – the active component in cannabis that makes people high but that is also thought to dull pain – binds to different molecular targets to produce the two effects. THC gives people a high by binding to a molecular anchor called the cannabinoid type-1 (CB1) receptor. Zhang’s team discovered that THC relieves pain by binding instead to receptors for the brain-signalling compound glycine, increasing their activity. Mice in which the glycine receptor is absent, or its activity blocked, experience pain even when given THC (Nature Chemical Biology, DOI: 10.1038/nchembio.552). Targeting glycine and CB1 receptor activity could be a way to develop non-psychoactive cannabis, Zhang says.
Boosted heat shock proteins fight Alzheimer’s SYMPTOMS of Alzheimer’s disease in mice have been eased by extra supplies of “heat shock” proteins, which re-fold or dispose of proteins implicated in the disease. Tohru Mizushima of Kumamoto University, Japan, and his colleagues used mice bred to mimic symptoms of Alzheimer’s. Half the mice were also engineered to make extra supplies of heat shock protein (HSP) 70 in their brains. The HSP70-boosted mice were much better than the others at finding their way around mazes,
and post-mortems showed their brains to be free of the characteristic beta-amyloid plaques that clog the brains of people with Alzheimer’s. That’s because the boosted mice produced normal – rather than high – levels of the amyloid precursor proteins from which plaques are made. What’s more, any plaques that did form were more readily removed. Mizushima’s team says that HSP70 amplifies the expression of chemicals such as insulindegrading enzyme and
transforming growth factor beta 1, linked to the destruction of the beta-amyloid proteins (Journal of Neuroscience, DOI: 10.1523/jneurosci.5478-10.2011). Elsewhere in the field, Nature Genetics carries reports of four new genes linked with Alzheimer’s disease by consortia in the US (DOI: 10.1038/ng.801) and Europe (DOI: 10.1038/ng.803). These genetic discoveries reinforce earlier gene studies implicating abnormal inflammation and fat metabolism in the disease. JQI/NIST
Like cannabis, but without the buzz
Prejudice linked to fertility cycle COULD racism be innate, a by-product of our evolutionary heritage? The idea has gained tentative support in recent years. It rests on the assumption that violent competition between groups of early humans encouraged our ancestors to fear outsiders. If this innate fear remains to this day, it may in part explain negative attitudes to people perceived as different. Carlos Navarrete and colleagues at Michigan State University in East Lansing tested an aspect of the hypothesis – that women have evolved a desire to avoid being sexually coerced by an unfamiliar man during their fertile period. The team randomly assigned 85 women to one of three colourcoded teams, and found that women who were ovulating showed a subconscious prejudice against men whose T-shirt colour identified them as belonging to a different team – these women were quicker to categorise words such as “spider” as negative when shown photographs of the men (Psychological Science, in press). Navarrete says the result may suggest that “racism is a by-product” of our evolution, but more study is needed.
Bye-bye electrons, hello atomtronics TIME to retire the old soldering iron? In the “atomtronic” circuits shown above, it’s atoms, not electrons, that flow. Previously, atoms have been made to flow from one point to another. To get them to flow round and round in a circuit, Kevin Wright and colleagues at the National Institute of Standards and Technology in Gaithersburg, Maryland, chilled 100,000 sodium atoms until they became a BoseEinstein condensate – a blob of floating atoms that behaves as a single, coherent quantum object. The researchers used a complex array of lasers to trap and shape the
blob into a torus. A further pair of lasers, one in a rotating configuration, gave the atoms just enough energy to circulate in unison around the ring, but not so much energy that the condensate decohered. This “current” of atoms flowed for 40 seconds, four times longer than atoms in previous experiments (Physical Review Letters, DOI: 10.1103/PhysRevLett.106.130401). Flowing atoms act like frictionless “superfluids”, which are highly sensitive to rotation, so such atom circuits might form the basis of ultrasensitive gyroscopes, says Wright.
9 April 2011 | NewScientist | 19
Brian Stablyk/getty
INGENIOUS experiments that have teased apart the mind-altering and pain-relieving effects of cannabis could open the way to related drugs that offer pain relief without causing unwanted highs. Medicinal cannabis is taken as a painkiller – to dull pain in cancer and multiple sclerosis for example – but it can produce unpleasant side effects such as hallucinations and impaired mobility. Now, Li Zhang at the US National Institute on Alcohol Abuse and Alcoholism in Bethesda, Maryland, and colleagues have shown that tetrahydrocannabinol (THC) – the active component in cannabis that makes people high but that is also thought to dull pain – binds to different molecular targets to produce the two effects. THC gives people a high by binding to a molecular anchor called the cannabinoid type-1 (CB1) receptor. Zhang’s team discovered that THC relieves pain by binding instead to receptors for the brain-signalling compound glycine, increasing their activity. Mice in which the glycine receptor is absent, or its activity blocked, experience pain even when given THC (Nature Chemical Biology, DOI: 10.1038/nchembio.552). Targeting glycine and CB1 receptor activity could be a way to develop non-psychoactive cannabis, Zhang says.
Boosted heat shock proteins fight Alzheimer’s SYMPTOMS of Alzheimer’s disease in mice have been eased by extra supplies of “heat shock” proteins, which re-fold or dispose of proteins implicated in the disease. Tohru Mizushima of Kumamoto University, Japan, and his colleagues used mice bred to mimic symptoms of Alzheimer’s. Half the mice were also engineered to make extra supplies of heat shock protein (HSP) 70 in their brains. The HSP70-boosted mice were much better than the others at finding their way around mazes,
and post-mortems showed their brains to be free of the characteristic beta-amyloid plaques that clog the brains of people with Alzheimer’s. That’s because the boosted mice produced normal – rather than high – levels of the amyloid precursor proteins from which plaques are made. What’s more, any plaques that did form were more readily removed. Mizushima’s team says that HSP70 amplifies the expression of chemicals such as insulindegrading enzyme and
transforming growth factor beta 1, linked to the destruction of the beta-amyloid proteins (Journal of Neuroscience, DOI: 10.1523/jneurosci.5478-10.2011). Elsewhere in the field, Nature Genetics carries reports of four new genes linked with Alzheimer’s disease by consortia in the US (DOI: 10.1038/ng.801) and Europe (DOI: 10.1038/ng.803). These genetic discoveries reinforce earlier gene studies implicating abnormal inflammation and fat metabolism in the disease. JQI/NIST
Like cannabis, but without the buzz
Prejudice linked to fertility cycle COULD racism be innate, a by-product of our evolutionary heritage? The idea has gained tentative support in recent years. It rests on the assumption that violent competition between groups of early humans encouraged our ancestors to fear outsiders. If this innate fear remains to this day, it may in part explain negative attitudes to people perceived as different. Carlos Navarrete and colleagues at Michigan State University in East Lansing tested an aspect of the hypothesis – that women have evolved a desire to avoid being sexually coerced by an unfamiliar man during their fertile period. The team randomly assigned 85 women to one of three colourcoded teams, and found that women who were ovulating showed a subconscious prejudice against men whose T-shirt colour identified them as belonging to a different team – these women were quicker to categorise words such as “spider” as negative when shown photographs of the men (Psychological Science, in press). Navarrete says the result may suggest that “racism is a by-product” of our evolution, but more study is needed.
Bye-bye electrons, hello atomtronics TIME to retire the old soldering iron? In the “atomtronic” circuits shown above, it’s atoms, not electrons, that flow. Previously, atoms have been made to flow from one point to another. To get them to flow round and round in a circuit, Kevin Wright and colleagues at the National Institute of Standards and Technology in Gaithersburg, Maryland, chilled 100,000 sodium atoms until they became a BoseEinstein condensate – a blob of floating atoms that behaves as a single, coherent quantum object. The researchers used a complex array of lasers to trap and shape the
blob into a torus. A further pair of lasers, one in a rotating configuration, gave the atoms just enough energy to circulate in unison around the ring, but not so much energy that the condensate decohered. This “current” of atoms flowed for 40 seconds, four times longer than atoms in previous experiments (Physical Review Letters, DOI: 10.1103/PhysRevLett.106.130401). Flowing atoms act like frictionless “superfluids”, which are highly sensitive to rotation, so such atom circuits might form the basis of ultrasensitive gyroscopes, says Wright.
9 April 2011 | NewScientist | 19